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Cadmium (Cd) is a heavy metal that may bring about harmful pollution of water and soil. Phytoremediation involving elements beneficial for plant development is a strategy to alleviate this problem. Silicon (Si) has shown potential in neutralizing biotic and abiotic stresses in plants, especially those caused by heavy metals. Thus, the aim of this study was to evaluate whether Si could mitigate the effects of Cd toxicity on growth, photosynthetic activity, and oxidative stress in seedlings of Enterolobium contortisiliquum. The experiment consisted of a completely randomized design with four replications. In addition to a control treatment, the following amounts of Cd, Si, and combinations were added to the complete nutrient solution: 1.5 mM Si; 3.0 mM Si; 1.5 mM Si + 100 µM Cd; 3.0 mM Si + 100 µM Cd; 100 µM Cd. Each sampling unit consisted of a tray containing 16 plants. Silicon concentrations of 1.5 and 3.0 Si mM were adequate to mitigate the effects of cadmium toxicity on Enterolobium contortisiliquum seedlings. The results showed that Si promoted photosynthetic activity, increased total chlorophyll, and decreased shoot lipid peroxidation in the presence of Cd. Furthermore, the lack of significant differences in shoot and root dry weight among treatments and low peroxidation content in roots suggest that E. contortisiliquum is tolerant to cadmium. [ABSTRACT FROM AUTHOR]

Lead (Pb) is a heavy metal considered one of the major soil pollutants. Phytoremediation is a sustainable and economically viable biological method for reducing Pb content in the environment. Inga uruguensis is a tree legume species that has characteristics favorable to phytoremediation, such as rapid growth and high biomass production. The objective of this work was an initial evaluation of tolerance and phytoremediation potential of I. uruguensis to Pb. The experiment was carried out in a greenhouse. In addition to the control, soil contamination was carried out with the following Pb doses: 100, 200, 300, 400, and 500 mg.dm?, with 5 repetitions in each treatment, totaling 30 vases. We assessed growth, number and mass of nodules, chlorophyll content, ureids, amino acid, protein and soluble carbohydrates in leaves, roots and nodules, tolerance index, dry matter, and tissues Pb content of I. uruguensis. The data were analyzed by the Tukey test using R and SISVAR software. There was no negative effect of Pb in soil on I. uruguensis growth, the symbiotic relationship with rhizobia was kept, even at high Pb content and the tolerance index was not lower than 0.69. Inga uruguensis has initial tolerance and potential to be used as phytoremediation in soils contaminated by Pb. [ABSTRACT FROM AUTHOR]

O ne of the main metals explored in the world is copper (Cu), a native element, which is rarely found pure in nature. The mining and processing of copper generates environmental debates due to the generation of polluting agents in the areas of concentration, smelting and refining, in addition to the negative impacts imposed on the vegetation and topography of the mined area. The study aimed to investigate the initial morphometric performance of the white ipe (Tabebuia roseo-alba (Ridl.) Sandwith) in a substrate composed of copper mining tailings and increasing percentages of organic matter, evaluate its phytoremediator potential and the Dickson's Quality Index (IQD). The experimental design was the entirely randomized one. Morphometric data of the treatment were collected regarding height, stem diameter and number of leaves of the plant species where they were later submitted to statistical and IQD analysis, in addition to calculations related to the index and translocation factor of copper in the plant and its phytoextracting capacity. The phytomass compartmentalized in roots and aerial part was collected, placed in a drying oven, ground and sent to the laboratory for the proper evaluation of the copper metal in the compartments of the plant species, in addition to the chemical evaluation of the substrate. It was concluded that white ipe has the potential to phytostabilize the copper element coming from mining tailings, as well as achieving a satisfactory IQD in treatment composed of 90% of mining tailings and 10% of organic matter. [ABSTRACT FROM AUTHOR]

One of the common contaminants, usually found in areas of landfill or old trash dumps, is slurry: a liquid residue with dark color and strong odor, originated from the degradation of organic matter. In some cases, heavy metals are found in its composition, besides other types of substances that cause direct contamination of the soil and close or underground water bodies. The purpose of this work was to verify the efficiency of Vetiver grass (Vetiveria zizanioides (L.) Nash.) in the process of phytoremediation in tropical soils contaminated with slurry from solid waste degradation. Laboratory tests were conducted to detect the efficiency of Vetiver in treating this contaminated soil and how much it is able to absorb the contaminating substances. Zinc parameters were analyzed in samples of roots, foliage, the soil used for the planting of Vetiver seedlings and the liquid resulting from the leaching process. Contaminated and decontaminated samples were used to obtain a comparison between the results, which were also analyzed by statistical methods. After 45 days, the Vetiver grass (Vetiveria zizanioides (L.) Nash.) was proven effective in the treatment of contaminated soil, especially in the removal of the heavy metal Zinc. However, considering that this effluent is a complex material, with a highly diversified composition, new evaluations using Vetiver grass must be established in order to better elucidate the use of this element in the treatment of leachate. [ABSTRACT FROM AUTHOR]

Fish farm ponds generate organic matter (OM) composed mainly of nitrogen (N) and phosphorous (P) which are usually released by the effluent without prior treatment to the receiving water body. To obtain the environmental license, the effluents generated by the aquaculture activity must comply with the recommendations contained in the legislation. In the State of São Paulo, the State Decree 62.243 of November 1, 2016 the rules and procedures for environmental licensing of São Paulo aquaculture are available, promoting actions to strengthen and encourage São Paulo aquaculture. In view of the need to regularize aquaculture enterprises, economically and environmentally viable technologies may become options for producers to regularize their activity. Artificial Floating Islands (AFIs) are alternative technology for the treatment of fish farming effluents and their efficiency in nutrient retention has been demonstrated. The present study discusses the role of this AFIs in relation to the adequacy of tilapia farming effluent of environmental legislation. For this purpose, six nurseries for fattening Nile tilapia with and without AFIs were used in this research. The results showed that among the variables analyzed, the phosphorous levels did not reach concentrations to adapt the current environmental legislation, that is, lower than 50 Îg L-1. The application of good management practices with better feed conversion and flow control can reduce the overload of this element on the system and thus allow better efficiency of nutrient retention by the AFIs. [ABSTRACT FROM AUTHOR]

This study uses the experimental research by phytoremediation technique, with the use of Canavalia ensiformis as a soil phytoremediation contaminated by slag, the analysis was done in five treatments under different doses of the contaminant (0, 32, 64, 128 and 256 grams). The results were submitted to analysis of variance and the means compared by 5% Tukey test. It can be concluded that the plant growth pattern was affected by the contaminant and the treatment 02 showed further development of the branch and biomass production compared to the others, and the Treatment 04 had lower branch growth rate followed by lower production biomass compared to other witnesses. [ABSTRACT FROM AUTHOR]

Phytoremediation is an alternative technique used to treat copper-contaminated soils. The objective of this research was to explore the behavior of nine summer cover crops regarding the growth, absorption and translocation of copper in soils with contamination levels exceeding the Value of Prevention, with a view to selecting plants for phytoremediation programs. In the experiments the Cambisol was contaminated with copper, added in doses of 0, 100, 200, 400, 500 and 600mg kg-1, in which the following nine plants were cultivated under greenhouse conditions: Canavalia ensiformis, Cajanus cajan, Dolichos lablad, Mucuna cinereum, Mucuna aterrima, Crotalaria juncea, Crotalaria spectabilis, Pennisetum glaucum and Paspalum notatum. At 90 days after sowing the plants were evaluated for dry mass of shoot and root, Cu, N, P, K, Ca, Zn, and Fe levels in the shoot and Cu in the roots. High soil Cu levels induced a decline in the phosphorus absorption by the plants. Canavalia ensiformis displayed high potential for phytoextraction as these plants could translocate high copper concentrations to the aerial plant parts, while the Mucuna cinereum and M. aterrima are indicated for the copper phytostabilization programs, due to the high copper accumulation in their root systems. [ABSTRACT FROM AUTHOR]

The objective of this work was to evaluate the action of three species of aquatic plants called Eichhornia crassipes, Pistia stratiotes and Salvinia auriculata in the removal of available N and P fractions from the effluent of a domestic sewage treatment system in the district of Montalvão, in Presidente Prudente/SP. The treatments were characterized in: (T1) = effluent without the presence of plants; (T2) = effluent with Eichhornia crassipes; (T3) = effluent with Pistia stratiotes; (T4) = effluent with Salvinia auriculata, following the completely randomized design, with four treatments, in subdivided plots, with five replications. The available NH4+, NO3- and P concentrations of the effluent and their contents in the plant tissue (roots, bulbs and leaves) were analyzed. There was removal of NH4+ and P by aquatic plants in relation to the control treatment; the NH4+ removal rates of the effluent were differentiated between the species and between the monthly evaluation cycles; the Eichhornia crassipes presented greater efficiency in the removal of P from the effluent during all the monthly evaluation cycles; Salvinia auriculata presented higher levels of NH4+ and P in the tissue (roots, bulbs and leaves). [ABSTRACT FROM AUTHOR]

Wastewater treatment systems for domestic effluents have high efficiency for reducing solids concentrations, chemical oxygen demand (COD), biochemical oxygen demand (BOD) and other organic compounds, however, are deficient for removal some nutrients such as nitrogen and phosphorus. Aquatic plants can be used in wastewater treatment, especially with regard to the post-treatment of effluents, in order to removal nutrients and other parameters not previously remedied. Thus, the aim of this study was to evaluate the efficiency of post-treatment wastewater by aquatic macrophyte Spirodela polyrhiza. To this purpose, 250 liters of post-treated wastewater were placed in a polyethylene reactor operating in batch for 42 days. Effluent samples were performed due to the hydraulic retention time (HRT), every 7 days. In effluent were evaluated the following parameters: dissolved oxygen (DO); temperature; pH; turbidity; total solids, fixed solids and volatile solids; COD; total nitrogen and total phosphorus concentrations. The results were satisfactory, observing maximum efficiency for removal of turbidity, N, P and COD of 99%, 100%, 100% and 88% respectively. It was observed that the plant senescence process might have been responsible for changes in turbidity and DO parameters. The macrophyte proved to be a great option for posttreatment of domestic sewage, as it requires for its development high levels of nutrients, thus assimilating these nutrients from the environment to which they belong. More studies are needed, as in Brazil Spirodela polyrhiza is still poorly studied. [ABSTRACT FROM AUTHOR]

Frequent or misuse of pesticides can result in contamination of the soil, water and food. To avoid such contamination the present study evaluated the potential of Melissa officinalis in soil phytoremediation containing a mixture of commercial pesticides Aminol and Herbipropanin (2,4-D and propanil). Soil samples (250.0 g) were spiked with three concentrations of the mixture of the commercial pesticides (0.1612 g kg-1 + 0.072 g kg-1; 0.0806 g kg-1 + 0.0403 g kg-1; 0.036 g kg-1 + 0.018 g kg-1, of Aminol and Herbipropanin respectively) where the seedlings were planted. Successive samplings that soil (10.0g) were conducted to carry out the extraction of these compounds with organic solvents (methanol / ethyl acetate 50:50 v/v) to be analyzed by high-performance liquid chromatography with diode array to assessing whether the compounds had decreased by the use of the plant. The results showed a decrease in the plant cultivated with compounds for 20 days of cultivation. This study showed that Melissa officinalis cultivation can be a fast, effective and low-cost strategy for phytoremediation of soils contaminated by 2,4-D herbicides and propanil, and also promising in the remediation of the metabolite 3,4-DCA. [ABSTRACT FROM AUTHOR]

At the global level, the problems of pollution in both soils and water and air are mainly due to anthropogenic activities; which include the extraction of natural resources, in this particular case of hydrocarbons. The environmental impact that is generated in Colombia due to this situation include the contamination of water sources, fauna and flora deteriodadas or drastic changes in the landscape. Therefore, government entities such as the Ministry of Environment and Sustainable Development and the National Agency for Licenses EnvironmentalANLA, have developed various strategies of control in order to reduce the impact on the environment. The objetive of this article is to elaborate a synthesis with information about soil and water pollution by hydrocarbons and evaluate phytoremediation as a biotechnology strategy for recovery. It was found that the main source of pollution in soil and water is mainly due to accidental spills during the exploration, extraction, transportation of hydrocarbons; with regard to the recovery, in recent times, there has arisen a phytoremediation as an effective technique to reduce environmental damage in addition to be aesthetically pleasing. [ABSTRACT FROM AUTHOR]

Aquatic Machropytes are used in constructed wetlands as treatment for dairy wastewater, which contain high organic load and euthrophyzation power when disposed without treatment. Considering the diversity and the unexplored potential from native aquatic flora, local aquatic macrophytes were aimed to decrease organic load from dairy effluents. The collected Macrophytes were Pistia stratoides, Polygonum sp. and Eichhornia paniculata. The dairy wastewater, with average COD of 7.414,63 mg/L, was diluted, whereas 4 (four) wetlands were established with COD values of 3.133,16 mg/L (D1) and another 4 (four) with 2.506,53 mg/L (D2). Analyses for COD, temperature, and pH were conducted. Pistia stratiotes did not resist the experimental conditions and died on the sixth day. The best organic load reduction were achieved with Polygonum sp. (87,5% COD) and with Eichhornia paniculata (90% COD) in the diluted sample D1. Therefore, both Eichhornia paniculata and Polygonum sp. were considered suitable for application in constructed wetlands to decrease organic load from dairy wastewater. [ABSTRACT FROM AUTHOR]

Currently tannery sludge, waste from leather processing industry, has been widely used in agriculture. This residue has nutrient content that can be used by plants, but has potentially toxic elements that can cause damage to the environment and human health. The objective of this study was to evaluate the effect of different ratios of tannery sludge used as substrate in the growth of plants açaizeiro and chemical changes occurring in the substrate 180 days after planting the plants. We used a completely randomized design with six replications. The treatments consisted of the following substrates: control (soil without tannery sludge), soil + 50 % of tannery sludge, soil + 70 % of tannery sludge, soil + 75 % of tannery sludge, soil + 80 % of sludge tannery and 100 % of tannery sludge. All plants were evaluated açaizeiro height, stem diameter, root length. And root dry weight, shoot and total. N, K, Ca, Mg, and Na contents: In the substrate the pH, organic matter and the contents of the chemical elements essences plants were evaluated. We also assessed the levels of potentially toxic element: Cd, Cr, Cu, Fe, Mn, Pb and Zn. The use of tannery sludge as substrate, decreased plant growth of açai, increased the contents essences of plants and the elements Na, and promote increased levels of potentially toxic elements. However, the increase in the levels of potentially toxic elements was in the range allowed by current environmental legislation in the country, in other words, at levels that do not cause environmental problems. [ABSTRACT FROM AUTHOR]

The phytoextraction of heavy metals using chelating agents has been widely studied for the remediation of contaminated soils. To evaluate the efficiency of EDTA-induced phytoextraction of Ba and Pb using Brachiaria decumbens for the remediation of soil contaminated by oil well drilling and exploration waste, an experiment was conducted by applying a single dose (6 mmol EDTA kg-1 soil) and split doses of EDTA (three applications of 2 mmol EDTA kg-1 soil). The samples were subjected to sequential extractions using the method proposed by Ure et al. (1993) as modified by Rauret et al. (1999).The application of EDTA did not influence the distribution of Ba in various chemical fractions of the soil. The dry matter production did not differ significantly between the treatments and the control, thereby demonstrating the tolerance of plants to the experimental conditions. The absorption of Pb by plants was influenced by the application of EDTA. The application of a single dose of EDTA influenced the absorption of Pb and its translocation to the aerial plant parts. The application of split doses favoured higher accumulation of Pb in roots. Because of its tolerance to heavy metals and EDTA, B. decumbens has the potential to be used in phytostabilisation. [ABSTRACT FROM AUTHOR]

Phytostimulation is a technique of phytoremediation that can be used to reduce the concentration of herbicides in the soil. It is necessary to select plants that stimulate the activity of the rizosphere degrading microorganism. The aim of this study was to evaluate the activity of the biodegradation of the herbicide compound formulated mixture of imazethapyr + imazapic (75 + and 25 g L-1) in rhizosphere soil from six plant species with potential for phytostimulation. Biodegradation of the herbicide in the rhizosphere soil of Canavalia ensiformis, Glycine max, Lolium multiflorum, Lotus corniculatus, Stizolobium aterrimum and Vicia sativa, and a control (soil without plant) was evaluated at doses of 0, 250, 500, 1.000 and 4.000mL 1 ha, by quantifying the production of C-CO2 of the soil and the degradation of the herbicide from the soil by liquid chromatography coupled to mass spectrometry. The production of C-CO2 of the soil after the contamination with the mixture imazethapyr + imazapic was higher in the rhizosphere soil of the six plant species when compared to soil not cultivated. The rhizospheric soil from Stizolobium aterrimum shouwed the highest degradation of the herbicide imazetapyr on the highest doses evaluated, being a promising specie for phytostimulation. [ABSTRACT FROM AUTHOR]

The wastewater treatments with floating macrophytes have proven effective in the remediation of waters with nutrient content, organic matter and toxic substances such as arsenic, zinc, cadmium, copper, lead, chromium, and mercury. Its importance lies in its ability to be used in rural communities due to their low consumption of conventional energy and practicality in the assembly and operation of treatment systems. Still, it has not been clarified thoroughly the processes taking place in the purification of wastewater with floating macrophytes. This article attempts to review the existing literature on floating macrophytes, thus identifying the general aspects, advantages and disadvantages of using these plants for treating wastewater. Similarly, identify the most important background since the beginning of this application. There will be described models and design criteria mostly employed, rigorously reviewing removal efficiencies of different species of floating macrophytes. Finally it will be addressed as discussed current perspectives and future challenges for the development of this technique. [ABSTRACT FROM AUTHOR]

Introduction. The heterogenous photocatalysis is useful as a pre treatment before the biological treatment of polluting agents which are resistant to biodegradation. The phytoremediation is used to degrade and to extract polluting agents from the environment. The combination of both techniques is a good alternative for the treatment of complexometric waste with complexometric indicators. Objective. To apply photo catalysis and phytoremediation to the complexometric waste generated in the Universidad del Cauca's laboratory of environmental and sanitary engineering. Materials and methods. A photoreactor was used for the photo-catalysis process and the conditions under which the highest degradation and mineralization percentages of the eriochrome black T (NET) indicator were analyzed. In the phytoremediation process, reactors with aquatic plants were used. The control was made by the use of foliage counts and chemical analysis. Results. The optimal conditions for the treatment of waste with NET were: 0, 3 g/L of TiO2 catalyst, 80 ppm of H2O2 and an UV light exposure time of three hours, obtaining a degradation percentage of 86.85%. In the phytoremediation process, the removal of salts expected was not achieved. Conclusion. The use of adequate TiO2 and H2O2 concentrations can achieve a good degradation percentage of the NET indicator contained in chemical waste. A more detailed study that allows the election of another type of biological treatment to complement the photo catalysis in order to achieve the salts removal, is recommended. [ABSTRACT FROM AUTHOR]

É preciso analisar as possibilidades ecologicamente sustentáveis de técnicas aplicadas na área agrícola, para recuperar e melhorar as áreas degrada devido ao uso exagerado de fertilizantes na plantação das culturas, tornando-os contaminados ou totalmente inférteis. As técnicas aplicadas será a da fitorremediação, que é o uso de leguminosas conhecidas também como adubo verde, que devido a sua capacidade simbiótica da fixação biológica de nitrogênio, transmiti para as raízes das plantas nutrientes capazes de agregar qualidade ao solo e retirar possíveis contaminantes causados pelo uso indevido dos agroquímicos, e reduzir consideravelmente o consumo de energia. O procedimento do uso da técnica está associado entre as leguminosas e bactérias dos gêneros Rhizobium sendo as principais fontes biológicas de nitrogênio, é importante que inicialmente introduza as bactérias nas sementes das leguminosas quando for plantada a primeira vez. Para realizar o processo da adubação verde é necessário que se conheça que tipo de leguminosa é adequado para a região, analisando o clima, condições do solo, físicas, químicas e biológicas. Para a região do Semiárido são as espécies de particularidades adaptáveis a baixa fertilidade do solo e a condições de seca, a adubo verde é um procedimento agrícola que tem como característica a utilização de um plantio direto, são potencializadores de vida para o solo, a sua utilização é avaliada em diversos campos onde ocorre poluentes sendo alguns deles metais pesados, pesticidas e óleos contaminantes, obtendo resultados bastante promissores, devido a utilização de plantas com capacidade de degradar determinados compostos. Porém a adubação verde irá obter sucesso, dependendo da associação da formação das áreas cultivadas para a produção de sementes, assim possibilitando o desenvolvimento sustentável nos agroecossistemas. [ABSTRACT FROM AUTHOR]